My laboratory is involved in studies to genetically modify autologous lymphocytes to improve their anti-tumor activity. In 1990 we reported the first studies of gene transfer in humans which involved the adoptive transfer of TIL transduced with a marker gene encoding neomycin phosphotransferase. These studies suggested the possibility that genes could be inserted into lymphocytes to improve their anti-tumor efficacy. We have now made progress in this area by developing techniques for the high efficiency transduction of human lymphocytes. The genes encoding high affinity anti-tumor T cell receptors (TCR) that recognize antigens on melanomas and common epithelial cancers have been identified and clinical trials to use autologous T cells transduced with these TCRs have begun. In recent studies we have shown that up to 30% of patients with metastatic melanoma will achieve objective clinical cancer regressions when treated with their autologous lymphocytes that have been transduced with T cell receptors that recognized the MART-1 or gp100 melanoma antigens. T cell receptors have now been identified that recognize NY-ESO-1, p53, and CEA epitopes. C+himeric antigen receptors have been developed that recognize the HER-2 cell surface antigen. Clinical trials will be performed to study the treatment of patients with common epithelial malignancies using these transduced cells.